The present invention relates generally to the field of network switching and more particularly to network switching systems that include pluggable transceiver modules (for example, SFP+ (small form-factor pluggable plus) transceivers).
A network switch or switching hub is a computer networking device that links network segments or network devices. A switch is a telecommunication device that receives a message from any device connected to it, and then transmits the message only to the device for which the message was meant. This makes the switch a more intelligent device than a hub, which receives a message and then transmits it to all the other devices on its network. The network switch plays an integral part in most modern ethernet local area networks (LANs). Switches exist for various types of networks including fiber channel, ethernet and others.
Some network switch systems use “pluggable transceivers” to receive and transmit communications as part of the system's functioning as a network switch. Some known types of pluggable transceivers include SFP, SFP+ and QSFP+ (quad small form-factor pluggable plus). Some network switch systems include multiple plug-in module connectors (for example, slot or socket connectors) with each connector being capable of removably receiving a pluggable transceiver. Herein, any computer that accepts one or more removable transceiver modules is referred to as a “transceiver-receiving computer.” Transceiver-receiving computers include, but are not limited to network switch type transceiver-receiving computers and switching hub type transceiver-receiving computers.
Some transceiver-receiving computer systems include one or more dedicated printed circuit board (PCB) assembly(ies), each of which includes one or more plug-in module connector(s). In this kind of transceiver-receiving system, the PCB assembly: (i) mechanically removably supports and removably secures the plug-in module connector(s); (ii) provides certain types of processing on signals sent to and/or received from the pluggable transceiver(s); and (iii) provides electrical power to the pluggable transceiver(s) and the processing components included in the PCB assembly.
An ASIC (application-specific integrated circuit) is an (IC) integrated circuit customized for a particular use, rather than intended for general purpose use. As feature sizes have shrunk and design tools improved, the maximum complexity and functionality possible in an ASIC has grown. Modern ASICs often include entire microprocessors, memory blocks including ROM (read only memory), RAM (random access memory), EEPROM (electrically erasable programmable read only memory), flash memory and other large building blocks. Some ASICs require multiple voltages. Some ASICs further require voltage sequencing, where one voltage is applied to a chip prior to another voltage, to properly initialize the device and/or avoid hardware damage. Some PCB assemblies of network switches, as discussed above, use one or more ASICs to help process signals sent to and/or received from their pluggable transceiver(s).
More specifically, some known types of ASICs for use in transceiver-receiving computers include: (i) switch ASICs that perform the network switching functionality for signals sent to and/or received from the pluggable transceiver(s); (ii) physical layer (PHY) ASICs for connecting to physical media; (iii) SerDes (serializer/deserializer) ASICs for providing a high speed signaling interface (SerDes machine logic may be built and/or programmed into the switch ASIC mentioned above); (iv) re-timer ASICs for re-clocking the data; (v) buffer ASIC(s) that serve as a buffer memory for incoming and/or outgoing transceiver signals; and/or (vi) XPS (cross point switch) ASICs for handling multiple inputs to be routed to different outputs (for example, a 2×2 cross point switch lets port A at input go to port A output or port B output). It is known that these various types of ASIC functions can be combined on a single chip and/or distributed over multiple chips. It is also known that at least some of these kinds of transceiver signal processing components can be implemented in forms other than an ASIC, such as being implemented by a general purpose IC or other programmable logic device. For example, the buffer memory may be implemented as a standard random access memory (RAM). Regardless of their specific form of implementation, these transceiver signal processing components: (i) generally require a supply of power when operational; (ii) will herein collectively be referred to as powered transceiver signal processing components (or PTSP components); (iii) for PTSPC involved in switching, these will herein sometimes be referred to as switching-related powered transceiver signal processing components (SPTSP components); and (iv) for PTSP components that are interposed between the plug-in module connector and the SPTSP components, these will herein sometimes be referred to as intermediate powered transceiver signal processing components (IPTSP components).